YEREVAN -- Opposition leader Levon Ter-Petrossian warned Armenia's leadership to hold fresh elections or face the kind of unrest that has rocked Arab states as he held his largest rally since the bloody suppression of his 2008 postelection protests in Yerevan on February 18, RFE/RL's Armenian Service reports.

His Armenian National Congress (HAK) alliance, meanwhile, told supporters to get ready for "very serious events."

Addressing at least 10,000 people who gathered in the city center, Ter-Petrossian drew parallels between the situations in Armenia and several Arab nations that have seen massive antigovernment protests in recent weeks.

He compared Armenian President Serzh Sarkisian with the deposed rulers of Egypt and Tunisia.

"The plight of our people is no better than the plight of the peoples of those countries, and Armenia's regime is no less dictatorial and hated than the regimes in those countries," he told the crowd before it marched through downtown Yerevan.

"Unless the authorities draw the right conclusions from those telling events, the same will happen in Armenia sooner or later, and the full responsibility for that will fall upon Serzh Sarkisian and the kleptocratic regime led by him," Ter-Petrossian said. "The only way to avoid undesirable developments is preterm parliamentary and presidential elections."

But senior members of the ruling Republican Party (HHK) insist that the antigovernment uprisings in Egypt and Tunisia will not spill over to Armenia.

"There are no grounds for a social revolt in Armenia," HHK spokesman Eduard Sharmazanov said on January 31. He said that unlike their Tunisian and Egyptian counterparts, Armenia's leaders are committed to carrying out far-reaching political and economic reforms.

"Social unrest becomes visible only after erupting," he said. "Accordingly, the day of a social explosion is as hidden and unexpected as 'Judgment Day.' And Serzh Sarkisian's 'Mubarakization' is just a matter of time."

The HAK leader pointed to ongoing small antigovernment protests in Yerevan and other parts of the country against a series of unpopular government decisions that affected some sections of the population such as car owners, street vendors, and market traders. He urged them to "politicize" their campaigns and join the HAK in fighting for leadership change in Armenia.

Ter-Petrossian and other speakers at the rally did not say whether the opposition bloc plans to launch a fresh campaign of nonstop, antigovernment demonstrations.

Levon Zurabian, the HAK's central office coordinator, said only that the bloc will hold its next rally on March 1, on the third anniversary of deadly clashes between Ter-Petrossian supporters and security forces which left 10 people dead.

"Please spread this information among the people and get ready for very serious events," Zurabian told the demonstrators. He did not elaborate.

Zurabian indicated earlier this week that the HAK's further actions will depend in large measure on attendance at its rallies, which steadily declined in 2009 and 2010.

The protest on February 18 was clearly the largest since March 2008. According to Zurabian the March 1 rally will be "much more powerful."

In his speech, Ter-Petrossian said the HAK is "constrained" by the unresolved conflict over the breakaway Azerbaijani region of Nagorno-Karabakh and the persistent threat of an Azerbaijani military offensive against Armenia and/or Karabakh.

"But the authorities can't endlessly exploit the Karabakh issue and subordinate the resolution of Armenia's internal problems to it," he warned.

The holding of fresh presidential and parliamentary elections has been the key HAK demand for the past three years. The Sarkisian administration has repeatedly rejected it, saying that the next polls will take place after the president and the current Armenian parliament serve out their terms in 2013 and 2012 respectively.